JPH0883700A - Control method and its device of electromagnet power source, and particle accelerator - Google Patents

Abstract

PURPOSE: To provide a highly accurate control system of an electromagnet power source suitable for a particle accelerator. CONSTITUTION: A current pattern Ir for imparting required excitation to an electromagnet 1 is stored in a memory 61. A voltage pattern Vr initially set in a memory 62 for realizing this current pattern Ir is imparted as a command value to an AVR(automatic voltage regulator) 51 via a calculator 54. The AVR 51 feedback-controls a converter 2 in accordance with a deviation ve between a command value Vr and an actual measured value vf. When the voltage pattern Vr is not appropriate, a calculator 56 outputs a current deviation ie between the current pattern Ir and an actual measured value if. An input means 66 of a repeat control part 6 takes the current deviation ie exceeding a specified value in time series and stores a current deviation pattern Ie corresponding to the current pattern Ir in the memory 63. A calculator 67 calculates a correction voltage pattern ΑVr based on the current deviation pattern Ie to correct the voltage pattern Vr of the memory 62.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a particle accelerator such as a synchrotron which operates cyclically, and relates to a control system for an electromagnet power source.

[0002]

2. Description of the Related Art The important thing in operating a synchrotron is
Generating a magnetic field for the particles to move in a predetermined closed orbit. This magnetic field is a composite of the individual magnetic fields generated by multiple electromagnets. Further, it is necessary to change the magnetic field strength in accordance with the change in momentum of the accelerated particles. Directly observing the magnetic field strength and performing feedback control is difficult from the viewpoint of high accuracy of 10 to ⁴ or more required for operation, and the current value is actually controlled.

Various control methods for electromagnet power supplies such as synchrotrons have been tried in the past. As a typical method, there is a method in which both the voltage command value and the current command value are given to the thyristor converter to operate. To create a pattern of each command value, first, a current command value that gives a predetermined magnetic field change is created as a current pattern. Next, the voltage pattern that the power supply should output to the electromagnet in order to pass this current pattern to the electromagnet is determined from the resistance value, the inductance, etc. of the electromagnet or the cable that is the load of the power supply.

According to this method, the control accuracy can be evaluated by observing the deviation between the current command value and the current feedback value. Therefore, once the operation is performed, the voltage pattern is corrected so that the observed current deviation approaches 0, and the operation is repeated with the newly obtained voltage pattern. It aims to perform highly accurate operation with a small deviation from the pattern, and an automated operation of this operation is called a repetitive control method.

As a typical publicly known document of the repetitive control system, there is "Repetitive Voltage Control of the Main Ring M".
agnet Power Supply for the KEK12GeV PS "(Particle
Ac-celerators, 1990, Vol.29, pp.133 to 138), or "VM for Heavy Particle Cancer Therapy (HIMAC) Main Accelerator Synchrotron", National Institute of Radiological Sciences
E control device "(Hitachi Zosen Gijutsu, December 1992, No. 53)
Vol. 4, No. 4, pp. 35-41).

[0006]

However, in the above-mentioned conventional control method of the electromagnet power source, there is a phenomenon that the current deviation cannot be made smaller than a certain value, no matter how many times the correction operation by the repetitive control is executed. , Was hindering the improvement of driving accuracy.

SUMMARY OF THE INVENTION An object of the present invention is to provide a control method and apparatus that overcome the problems of the prior art described above and can greatly reduce the current deviation and improve the control accuracy of the electromagnet power supply.

An object of the present invention is to provide a particle accelerator capable of generating a highly accurate magnetic field pattern with a small beam adjustment burden and improving the beam quality.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electromagnet power supply which sets a target value of a waveform of a current flowing through an electromagnet in a predetermined cycle and corrects a voltage waveform applied to the electromagnet so as to realize the target value. In the control method, the voltage waveform is given as a command value to an automatic voltage control system (AVR), feedback control is performed according to a voltage deviation from an actually measured voltage of an electromagnet, and the target value and an actually measured current flowing through the electromagnet are compared. This is achieved by performing repetitive control for repeatedly correcting the voltage waveform so that the current deviation is reduced.

Another object of the present invention is to set a target value of a current waveform flowing through an electromagnet in a predetermined cycle to an automatic current control system (hereinafter referred to as A
CR), feedback control is performed according to the current deviation from the actual current of the electromagnet, and the command value of the voltage waveform applied to the electromagnet in order to realize the target value and the output of the ACR are supplied to the automatic voltage control system (hereinafter , AVR) and feedback control is performed according to the voltage deviation from the measured voltage of the electromagnet, when the current deviation is larger than a preset threshold value. The repetitive control for repetitively correcting the voltage waveform applied to the electromagnet to achieve the target value is performed, and the period of this repetitive control is achieved by cutting off the output from the ACR to the AVR.

Further, an object of the present invention is to generate a magnetic field by applying a voltage from a plurality of electromagnets that generate a magnetic field forming a closed orbit of particles and a converter whose firing angle is controlled, to the electromagnet. Equipped with an electromagnet power supply for supplying the electric current and a power supply control device for controlling the firing angle of the converter in order to generate the magnetic field in a predetermined pattern. However, in the particle accelerator that performs periodic operation to emit as high-energy particles, the power supply control device is a current waveform storage unit that sets a trapezoidal current waveform for applying a magnetic field in the predetermined pattern as a target value in advance. , An automatic voltage for feedback-controlling the firing angle of the converter according to the voltage deviation between the command value of the voltage waveform that realizes the target value and the measured voltage applied to the electromagnet. Control means (hereinafter, AVR) and the voltage waveform so as to reduce the current deviation when the periodic operation is started or when the current deviation between the target value and the actually measured current flowing through the electromagnet is equal to or more than a threshold value. It is achieved by providing a repetitive control means for correcting

[0012]

The present invention has been made by paying attention to the following points.

In the conventional control method, the current deviation, which is the basis for calculating a new voltage pattern obtained from the result of a certain operation, is included in the voltage pattern used for the operation and is finally obtained. Brazing is due to an error in comparison with the completed voltage pattern, and automatic current control means (hereinafter AC
R) also includes the result of control calculation to bring the pattern closer to a predetermined current pattern. That is, since the ACR acts so as to compensate for the voltage pattern at the unfinished stage, no matter how many times the repetitive control is executed, the action of the ACR adversely affects the unfinished voltage before it converges to the ideal voltage pattern. It stays in the state of the pattern.

As the operation of the electromagnet power supply control according to the present invention, the current deviation is used only for the repetitive control for correcting the voltage pattern and the ACR operation is not performed. Therefore, the influence of the current deviation due to the incomplete voltage pattern is repetitively controlled. Never appears in. Therefore, the current deviation faithfully reflects the error between the ideal voltage pattern and the unfinished voltage pattern. Therefore, by repeatedly correcting the voltage pattern to bring the current deviation close to 0, the current deviation is greatly reduced compared to the conventional one. This enables high-precision operation of the electromagnet power supply.

As another operation of the electromagnet power supply control according to the present invention, the output of the ACR based on the current deviation is given as the input of the AVR together with the voltage pattern, but the input to the AVR is cut off during the execution of the repetitive control. It Therefore, since only the error of the voltage pattern is reflected in the current deviation, the correction amount of the voltage pattern based on the evaluation of the current deviation is not affected by the ACR operation, and only the error amount of the voltage pattern can be correctly corrected. Becomes

According to this, the ACR can be disabled during the repetitive control period such as the start-up, and the effect of suppressing the disturbance due to the ACR can be exerted during the normal operation after the end of the repetitive control, and the high power of the electromagnet power supply can be obtained. Accurate and stable operation becomes possible. The ACR unavailable period can be limited to a part of the repetitive control period.

As a function of the particle accelerator of the present invention, a magnetic field forming a closed orbit of accelerated particles can repeatedly obtain a desired trapezoidal pattern with a current pattern extremely close to a target, so that the burden of beam adjustment is greatly reduced. There is an effect that it is possible to provide a high-quality particle beam that has a small ripple and high reproducibility.

[0018]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 2 shows the overall structure of a particle accelerator to which the present invention is applied. The accelerator shown in the drawing is a synchrotron, and low-energy particles are injected, the magnetic field is increased in proportion to the momentum of the particles as they are accelerated, and when the acceleration is completed, they are emitted to the next-stage accelerator or the like. The synchrotron repeats this series of operations at a cycle of 1 to several seconds.

The deflecting electromagnet 1B, the focusing electromagnet 1Qf and the diverging electromagnet 1Qd are called main electromagnets and generate a magnetic field forming a closed orbit. These three types of electromagnets are respectively excited by power sources 2B, 2Qf, 2Qd configured by power converters. Each power source 2 has a converter controller 5B, 5
Firing angle control and feedback control are performed by Qf and 5Qd. Repetitive control devices 6B, 6Qf, 6Qd take in the current deviation, determine a voltage pattern that is a control command value, and apply it to converter control device 5.

FIG. 1 is a block diagram of an electromagnet power supply controller according to a first embodiment of the present invention. Since the electromagnet power supply control device has the same configuration for each of the deflection electromagnet 1B, the focusing electromagnet 1Qf, and the diverging electromagnet 1Qd, one of them (for example, the deflection electromagnet) is generally shown.

A plurality of electromagnets 1 are connected in series and excited by one power source 2. The power supply 2 is a thyristor or G
It is a voltage source composed of a converter such as a TO. The output voltage vf of the converter 2 is the voltage divider 3, and the output current if is DCC.
It is measured at T4 and fed back to the converter control device 5. The converter control device 5 is provided with an AVR 51 that performs feedback control to control the voltage applied from the converter 2 to the electromagnet 1, and outputs its output signal (EC command) by an automatic transfer device (APPS) 52. Convert to the ignition pulse of.

The repetitive control device 6 includes a current pattern memory 61, a voltage pattern memory 62, a current deviation input means 66, a current deviation pattern memory 63, a correction voltage pattern calculator 62, and a voltage pattern correction circuit 68. It has functions.

In the case of the synchrotron, the current pattern Ir of the exciting current has a predetermined time waveform set as a target value in advance and is stored in the current pattern memory 61. In addition,
The current pattern memory 61 may be provided in a place other than the repeat controller 6.

The current pattern Ir shows a trapezoidal shape, and low-energy particles are injected into the synchrotron in a section where the current value is low, the current is increased as the particles accelerate, and the magnetic field of the electromagnet is increased. Particles are emitted from the synchrotron during the maximum period.

On the other hand, the voltage pattern Vr is a command value of the AVR 51, and is a voltage waveform applied from the converter 2 to the electromagnet 1 in order to realize the current pattern Ir of the target value.
The initial value is calculated from the current pattern Ir and the resistance R and inductance L of the electromagnet 1 which is the load of the power supply circuit and the cable, and is set in the voltage pattern memory 62.

[0027]

## EQU1 ## Vr = L (dIr / dt) + RIr The current pattern Ir and the voltage pattern Vr are output from the respective output devices 64 and 65 to the converter control device 5.

The voltage pattern Vr is calculated by the voltage deviation calculator 54.
To the voltage output value vf (feedback value) to calculate the voltage deviation ve. AVR51 This voltage deviation ve
According to the above, the above feedback control is performed.

At this time, if the voltage pattern Vr is not an appropriate voltage pattern for realizing the current pattern Ir, the current deviation ie between the current pattern Ir and the actual measured current if.
Is output from the current deviation calculator 56. The input device 66 takes in the current deviation IE, compares it with a preset threshold value imin, and if IE ≧ imin, stores IE in the current deviation pattern memory 63 in time series to create the current deviation pattern Ie. To do. The collection period T ₁ of the current deviation ie is controlled by the correction control circuit 68, and normally the current pattern Ir
1 cycle of is taken in.

When the current deviation pattern Ie is created,
The correction control circuit 68 activates the correction voltage pattern calculator 62 and calculates the correction voltage pattern ΔVr according to (Equation 2). The period T ₂ is a calculation period from the completion of calculation to the end, but the current pattern I including a margin in the calculation period
A period corresponding to one or a plurality of cycles of r may be set.

[0031]

ΔVr = KF (Ie) Here, the control gain K is a correction voltage value (v) per current deviation 1 (A). The function F is a process performed to extract reproducible current deviation data, and is, for example, an averaging operation for several cycles or a low-pass filtering process. Power supply capacity is 2kA
In the case of the degree, parameter processing such as K = 0.01 and F = 1.0 Ie is actually performed.

The correction control circuit 68 adds the correction voltage pattern ΔVr calculated by the calculator 62 to the voltage pattern Vr of the voltage pattern memory 62 to obtain the voltage pattern Vr.
Update r with period T ₃ . The updated Vr is output from the output device 65 in the next repetitive control cycle, and the series of controls described above is repeatedly performed until the current deviation ie becomes equal to or less than the threshold value. It should be noted that the repetitive control may be completed by counting the number of repetitions by the correction control circuit 68 and exceeding the designated number of times.

As shown in the figure, both the voltage pattern memory 62 and the current deviation pattern memory 63 have a double buffer structure. As a result, it is possible to employ an alternate buffer system in which each buffer currently used for control or acquisition and each buffer used for correction processing are alternately switched, and continuous repetitive control becomes possible.

FIG. 3 shows a timing chart of repetitive control according to one embodiment. In repetitive control, first,
Target current pattern Ir and initially set voltage pattern V
Based on r, power supply operation for one cycle to several cycles is executed to obtain current deviation pattern Ie data.

The subsequent waveform state is shown in the figure, and the current pattern Ir is a trapezoidal waveform which is repeatedly applied in a cycle of 1 to several seconds (usually about 2 seconds). Voltage pattern Vr,
The current deviation pattern Ie is also output or generated in the same cycle.

The repetitive control cycle includes a plurality of cycles of the current pattern, the current pattern Ie is generated in the period of T ₁ , and T ₂
The correction voltage pattern ΔVr is generated in the period of and the voltage pattern Vr is corrected in the period of T ₃ , but a plurality of cycles of the current pattern including these are set. According to the above-mentioned alternate buffer system, the period of T _{1 and} the period of T ₂ ~ can be simultaneously advanced, and the repetitive control cycle is further shortened.

By the above-mentioned repetitive control, the current deviation IE
When the value becomes sufficiently small, the repetitive control is completed and the accelerator is put into full-scale operation. During operation, monitor the current deviation ie,
When it exceeds the predetermined value, the repetitive control is executed again. In the illustrated example, the current deviation ie becomes less than or equal to the threshold value in the third repeat control, and the repeat control is ended. That is, the voltage pattern is not corrected until the current deviation ie becomes large again due to disturbance or the like, and the accelerator is in a normal operating state.

According to this embodiment, the arithmetic unit 56
The deviation output ie of is used only for the repetitive control and not for the current feedback control, so that the so-called ACR operation is not performed. Therefore, the influence of the current deviation ie caused by the uncompleted voltage pattern Vr does not appear in the repetitive control via the ACR operation. That is, the current deviation IE faithfully reflects the error between the ideal voltage pattern and the uncompleted voltage pattern. Therefore, by repeatedly correcting the voltage pattern that brings the current deviation IE closer to 0, the current deviation can be significantly reduced compared to the conventional one. And it is possible to operate the electromagnet power source with high precision.

As a result, the electromagnet is repeatedly excited with the target current pattern, the accelerator has high reproducibility, the quality of the particle beam is improved, and the burden of beam adjustment is significantly reduced.

Next, a second embodiment of the present invention will be described.
FIG. 4 is a block diagram of an electromagnet power source control device according to the second embodiment, which is the same as the configuration of FIG.
A switch circuit 57 for turning on / off the connection between 53 and the adder 55 is added.

The adverse effect of the ACR system appears in the current deviation collecting period of the repetitive control. Therefore, if this period is avoided, the ACR has a feedback effect with respect to external disturbances (disturbances of the electric power system, temperature changes, etc.), and therefore it is preferable to have the ACR.

Therefore, the switch circuit 57 controls the output signal V of the ACR 53 during the entire or part of the repetitive control.
cut off i. In the present example, the correction control circuit 68 turns off the switch circuit 57 during the collection period T ₁ of the current deviation ie so that the output signal Vi of the ACR 53 is not input to the AVR 51.

A period other than the above, that is, a period T in which the correction voltage pattern calculator 67 performs the processing period T ₂ of (Equation 2) and the correction voltage ΔVr are added to the original voltage pattern Vr.
_{In 3} , the switch circuit 57 is turned on and the ACR5
Feedback control is performed by 3 so that the current deviation ie becomes small.

According to the method of this embodiment, the voltage pattern V
As the repetitive control is advanced, r approaches the ideal voltage pattern in which the current deviation ie becomes 0 as much as possible, and the voltage pattern is completed. Moreover, the function of the ACR system has the effect of suppressing its influence on disturbances (changes in the power system, temperature, etc.).

Although the cutoff period of the output signal Vi of the ACR 53 is set to T ₁ , it may be set to the entire period until the repetition control is completed. Further, although the cutoff of the output signal Vi of the ACR 53 is realized by the on / off operation of the switch circuit 57, various modifications can be made such that the gain of the ACR 53 is set to 0 or sufficiently small during the cutoff period.

[0046]

According to the control system of the electromagnet power supply of the present invention, the repetitive control for correcting the voltage pattern is not adversely affected by the ACR operation, so that a desired voltage pattern for realizing the target current is created. Is possible,
Highly accurate operation of the electromagnet power supply can be realized.

Further, according to the particle accelerator of the present invention, since the highly accurate operation of the electromagnet power source can be realized, the burden of adjusting the particle beam can be greatly reduced and the quality (reproducibility and ripple) of the particle beam can be reduced. There is an effect that can be improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an electromagnet power supply control device according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a particle accelerator to which the present invention is applied.

FIG. 3 is a timing chart illustrating a repetitive control operation of the electromagnet power supply control device.

FIG. 4 is a configuration diagram of an electromagnet power supply control device according to a second embodiment of the present invention.

[Explanation of symbols]

1 ... Electromagnet, 2 ... Power supply (converter), 3 ... Voltage divider, 4 ... D
CCT, 5 ... Converter control device, 51 ... AVR, 52 ... Automatic phase shifter, 53 ... ACR, 54 ... Voltage deviation calculator, 55
... Adder, 56 ... Current deviation calculator, 57 ... Switch circuit, 6 ... Repeat control device, 61 ... Current pattern memory,
62 ... Voltage pattern memory, 63 ... Current deviation pattern memory, 64, 65 ... Output device, 66 ... Input device, 67 ...
Correction voltage pattern calculator, 68 ... Correction control circuit.

Claims (14)

[Claims] 1. A method of controlling an electromagnet power supply, wherein a target value of a current waveform flowing through an electromagnet is set at a predetermined cycle, and a voltage waveform applied to the electromagnet is corrected so as to realize the target value. Automatic voltage control system (AVR)
Feedback control is performed according to the voltage deviation from the actual measured voltage of the electromagnet, and repetitive control is performed to repeatedly correct the voltage waveform so that the current deviation between the target value and the actually measured current flowing through the electromagnet is reduced. A method of controlling an electromagnet power supply, which is characterized in that: 2. The repetitive control according to claim 1, wherein the repetitive control collects the current deviation in a time series of at least one cycle of the current waveform to create a current deviation pattern, and based on this pattern, the current deviation is set to 0. A method of controlling an electromagnet power supply, characterized in that a correction voltage pattern that approaches the above is created, and the voltage waveform is corrected or updated by this correction voltage pattern. 3. The method of controlling an electromagnet power source according to claim 2, wherein the current deviation pattern is created by adding low-pass filtering processing or averaging processing of a plurality of cycles. 4. The repetitive control according to claim 1, 2 or 3, wherein the repetitive control is terminated when the current deviation becomes equal to or less than a preset threshold value or when the repetitive control is performed a predetermined number of times. And a method for controlling an electromagnet power supply. 5. A target value of a current waveform flowing through an electromagnet in a predetermined cycle is given to an automatic current control system (hereinafter referred to as ACR), and feedback control is performed according to a current deviation from an actually measured current of the electromagnet to realize the target value. In order to achieve this, the command value of the voltage waveform applied to the electromagnet and the output of the ACR are given to an automatic voltage control system (hereinafter referred to as AVR), and feedback control is performed according to the voltage deviation from the actually measured voltage of the electromagnet. In the control method for the electromagnet power supply, when the current deviation is larger than a preset threshold value, iterative control is performed to repeatedly correct the voltage waveform applied to the electromagnet so as to achieve the target value. A method of controlling an electromagnet power supply, characterized in that the output from the ACR to the AVR is shut off during a period of repetitive control. 6. The repetitive control according to claim 5, wherein a period that is an integral multiple of the predetermined period is one cycle, and the current deviation is collected for at least one cycle of the current waveform to create a current deviation pattern. 1 period, a second period for creating a correction voltage pattern for making the current deviation closer to 0 based on this pattern, and a third period for correcting or updating the voltage waveform by the correction voltage pattern. A characteristic method for controlling an electromagnet power supply. 7. The method of controlling an electromagnet power source according to claim 6, wherein the output of the ACR is cut off during the first period. 8. An electromagnet, one or a plurality of electromagnets, a converter for supplying a current corresponding to a preset target value of a current waveform to the electromagnet, a command value of a voltage waveform for realizing the target value, and the electromagnet. In a control device for an electromagnet power supply, which comprises an automatic voltage control means (AVR) for feedback-controlling the firing angle of the converter according to a voltage deviation from an actually measured voltage applied, the target value and an actually measured current flowing through the electromagnet. A control device for an electromagnet power supply, comprising repetitive control means for repetitively correcting the voltage waveform so that the current deviation between 9. The current deviation pattern management means according to claim 8, wherein the repetitive control means collects the current deviation in time series by an amount corresponding to the current waveform to create and store a current deviation pattern, and Correction voltage pattern creating means for creating a correction voltage pattern for making the current deviation close to 0 based on the current deviation pattern;
A control device for an electromagnet power supply, comprising: a voltage waveform management unit that corrects, updates, or stores the voltage waveform according to the correction voltage pattern. 10. One or a plurality of electromagnets, a converter for supplying a current corresponding to a target value of a preset current waveform to the electromagnet, and a current deviation between the target value and a measured current flowing through the electromagnet. An automatic current control means (hereinafter referred to as ACR) that performs feedback control according to the command value of the voltage waveform applied to the electromagnet to realize the target value, and a voltage deviation between the output of the ACR and the actually measured voltage of the electromagnet. Accordingly, in a control device for an electromagnet power source including an automatic voltage control means (hereinafter, AVR) for feedback controlling the firing angle of the converter, a correction means for correcting the voltage waveform so as to realize the target value. During the execution period of this correction means, the AC
A repetitive control unit including a switching instruction unit that outputs a cutoff command that cuts off the output from R to the AVR and a determination unit that performs the correction process when the current deviation is larger than a threshold value. Control device for electromagnet power supply. 11. The current deviation pattern management means according to claim 10, wherein the correction means collects the current deviation in time series by an amount corresponding to the current waveform to create and store a current deviation pattern, and the current deviation pattern management means. A correction voltage pattern creating means for creating a correction voltage pattern for making the current deviation closer to 0 based on the deviation pattern, and a voltage waveform managing means for correcting, updating, and storing the initially initialized voltage waveform by the correction voltage pattern. The switching instruction means controls switching of creation of the current deviation pattern, creation of the correction voltage pattern, and correction or update of the voltage waveform, and outputs the cutoff command on during the creation period of the current deviation pattern. A control device for an electromagnet power supply characterized by: 12. The control device for an electromagnet power supply according to claim 9, wherein the current deviation pattern management means and / or the voltage waveform management means is configured to include an alternation buffer. 13. A plurality of electromagnets that generate a magnetic field that forms a closed orbit of particles, and an electromagnet that applies a voltage to the electromagnets from a converter whose firing angle is controlled to supply a current for generating the magnetic field. A power supply and a power supply control device for controlling the firing angle of the converter to generate the magnetic field in a predetermined pattern are provided. In the particle accelerator that performs a periodic operation to emit as, the power supply control device realizes the target value and a current waveform storage unit that sets a trapezoidal current waveform for applying a magnetic field in the predetermined pattern as a target value in advance. Automatic voltage control means for feedback controlling the firing angle of the converter in accordance with the voltage deviation between the command value of the voltage waveform to be applied and the measured voltage applied to the electromagnet (hereinafter referred to as AV ) And when the periodic operation is started or when the current deviation between the target value and the actually measured current flowing through the electromagnet is equal to or more than a threshold value, the repetitive control means for correcting the voltage waveform so as to reduce the current deviation. A particle accelerator comprising: 14. The power supply control device according to claim 13, wherein the power supply control device performs automatic feedback control according to the current deviation (hereinafter referred to as ACR), and between the output unit of the ACR and the input unit of the AVR. A particle accelerator characterized by comprising a switch device for shutting off during execution of the repetitive control means.